Technical Field
The invention relates to field of display technology, and particularly to an array substrate, a method of manufacturing the array substrate and a display device.
Description of the Related Art
Organic Light-Emitting Diode (OLED) is a current mode semiconductor Light-Emitting device based on an organic material. Recently, a display device which is characterized in including OLED has been developed to have a large size, a high resolution and a fast response. In order to reduce cost and improve displaying quality of a display panel, an oxide thin film transistor (TFT) array substrate, which is formed in a copper+oxide coplanar structure, is approached. As copper is used to form source and drain electrodes, the array substrate has advantages including low wire resistance, good conductive effect, lower voltage drop and lower process complexity in a large-size display panel, etc., and thus is widely concerned.
The existing oxide TFT array substrate formed in a copper+oxide coplanar structure has a configuration as shown in FIG. 1. The array substrate includes a base substrate 1001, a gate metal pattern 1002 formed on the base substrate 1001, a gate insulating layer 1003 formed over the gate metal pattern 1002, a source-drain metal pattern 1004 formed by depositing a source-drain metal (which is copper) on the gate insulating layer 1003 and patterning it, an oxide trench pattern 1005 formed by depositing an oxide active layer and patterning it, and a conventional passivation layer (PVX) 1006 and an organic film 1007 formed over the oxide trench pattern 1005, in which the PVX has a double-layer structure generally including a silicon oxide (SiOx) layer and a silicon nitride (SiNx) layer.
In this array substrate, the source-drain metal pattern 1004 is formed by the source-drain metal in a double-layer structure and has a thinner lower barrier layer, which is made of molybdenum-niobium alloy, and an upper copper metal layer. However, as the oxide trench pattern 1005 is located on the upper copper metal layer, the copper metal layer is completely exposed to an oxygen enriched environment and thus tends to be oxidized. Meanwhile, as shown in FIG. 1, when the lower layer of the PVX 1006 is SiOx and the upper layer is SiNx, the SiOx that is in contact with the source-drain metal pattern 1004 will accelerate oxidation of the copper metal layer. Otherwise, when the lower layer of the PVX 1006 is SiNx and the upper layer is SiOx, hydrogen (H) element in SiNx that is in contact with the oxide trench pattern 1005 will adversely affect the oxide trench pattern 1005, resulting in a large current phenomenon in the array substrate. In this instance, the copper metal layer will be oxidized to a large extent and the array substrate has a worse display performance.